docs: def main(_):
    """Create or load configuration and launch the trainer."""
    utility.set_up_logging()
    if not FLAGS.config:
      raise KeyError('You must specify a configuration.')
    logdir = FLAGS.logdir and os.path.expanduser(os.path.join(
        FLAGS.logdir, '{}-{}'.format(FLAGS.timestamp, FLAGS.config)))
    try:
      config = utility.load_config(logdir)
    except IOError:
      config = tools.AttrDict(getattr(configs, FLAGS.config)())
      config = utility.save_config(config, logdir)
    for score in train(config, FLAGS.env_processes):
      tf.logging.info('Score {}.'.format(score))